Question 1

The third expression appearing in the header of a for loop is the ____________, which executes at the end of each iteration. It usually increments the loop's counter variable.

Accepted Answer

The third expression in the header of a for loop is the update expression, which executes at the end of each iteration. It usually increments the loop's counter variable. The initialization expression initializes the counter variable at the beginning of the loop, and the test expression determines whether the loop should continue executing.

Question 2

The ____________ is specifically designed for situations requiring a counter variable to control the number of times a loop iterates.

Accepted Answer

The for loop is specifically designed for situations requiring a counter variable to control the number of times a loop iterates. It has a built-in counter and a defined start, stop, and step size, making it ideal for iterating over a specific range of values. The while loop and if-else statement do not have a built-in counter and would require additional code to control the number of iterations. The switch statement is used to select one of many code blocks to execute based on a specific condition, and does not involve any iteration control.

Question 3

The increment operator is ____________.

Accepted Answer

The increment operator is denoted by "++" and is used to increase the value of a variable by 1. It can be used in prefix form (e.g., "++x") or postfix form (e.g., "x++").

Question 4

Each time a loop executes its statement or statements, we say the loop is performing a(n) ____________.

Accepted Answer

The term "iteration" is commonly used in programming to refer to each time a loop executes its statement or statements.

Question 5

ListBox controls have an ____________ property that reports the number of items stored in the ListBox.

Accepted Answer

The correct property to use in order to determine the number of items in a ListBox control is the Items.Count property. This property returns an integer value that represents the number of items in the ListBox. The other options are not valid properties for determining the number of items in a ListBox control.

Question 6

The ____________ begins with the word while, followed by a Boolean expression that is enclosed in parentheses.

Accepted Answer

A "while clause" is the correct term for a statement that begins with the word "while," followed by a Boolean expression enclosed in parentheses, typically used to initiate a loop that continues as long as the Boolean expression evaluates to true.

Question 7

The first expression appearing in the header of a for loop is the ____________, which usually assigns a starting value to a counter variable.

Accepted Answer

The initialization expression is the first expression in the header of a for loop and it assigns an initial value to the counter variable.

Question 8

To add an item to a ListBox control with code, you call the control's ____________method.

Accepted Answer

The correct method to add an item to a ListBox control with code is Items.Add. This method adds the specified item to the end of the ListBox control.

Question 9

ListBox controls have an ____________ method that erases all the items in the Items property.

Accepted Answer

The Items.Clear method erases all the items in the Items property of a ListBox control. The other choices (Items.Erase, Items.Remove, and Items.Reset) are not valid methods for clearing the items in a ListBox.

Question 10

To ____________ a variable means to increase its value by 1.

Accepted Answer

The correct choice is "increment" as it means to increase a variable's value by 1. "Append" refers to adding something to the end of a list or string, "decrement" means to decrease a variable's value by 1, and "add" is too general and can refer to increasing a variable's value by any amount, not just 1.

Question 11

To ____________ a variable means to decrease its value by 1.

Accepted Answer

Decrementing a variable means reducing its value by 1.

Question 12

The while loop is known as a ____________, which means it tests its condition before performing each iteration.

Accepted Answer

The while loop is a pretest loop because it tests its condition before executing the body of the loop. It will only execute the body of the loop if the condition is true.

Question 13

____________ are commonly used to control the number of times a loop iterates.

Accepted Answer

Counter variables are specifically used for controlling the number of iterations in a loop. They are initialized to a starting value, and then incremented or decremented with each iteration of the loop until a certain condition is met. Choice A (Boolean variables) are used for true/false conditions, choice B (Sentinel variables) are used to signal the end of input in a loop, and choice D (Named constants) are variables that have a fixed value throughout the program and do not change.

Question 14

The ++ and -- operators can be written before their operands, which is called ____________.

Accepted Answer

The ++ and -- operators can be written before their operands, which is called prefix mode.

Question 15

The statement or block of statements following the while clause is known as the ____________ of the loop.

Accepted Answer

The block of statements following the while clause is known as the body of the loop. This is where the code to be executed repeatedly is written.

Question 16

The second expression appearing in the header of a for loop is the _____________, which is a Boolean expression that determines whether the loop will repeat.

Accepted Answer

The test expression is the second expression appearing in the header of a for loop and it is a Boolean expression that determines whether the loop will repeat. The initialization expression is the first expression and it sets the initial value of the loop variable. The update expression is the third expression and it updates the loop variable after each iteration. The control expression is not a commonly used term in for loops.

Question 17

The decrement operator is ____________.

Accepted Answer

The decrement operator is represented by "--" and it subtracts 1 from the variable it is applied to. Therefore, the correct choice is B.

Question 18

If a loop does not have a way of stopping, it is called a(n) ____________.

Accepted Answer

An infinite loop is a loop that runs indefinitely because there is no condition to stop the loop. It can cause the program to crash or become unresponsive, which is why it is important to avoid creating infinite loops in programming.

Question 19

When the ++ and -- operators are written after their operands it is called ____________.

Accepted Answer

The ++ and -- operators when written after their operands denote postfix mode. In postfix mode, the operators are applied after the operand, meaning the operand value is first used in the expression and then incremented or decremented.

Question 20

Because the for loop tests its Boolean expression before it performs an iteration, it is a ____________.

Accepted Answer

The given description matches the definition of a pretest loop, which tests its Boolean expression before performing the iteration. The other options are not applicable in this case.

Quiz 5: Loops, Files, and Random Numbers